This invention relates to bis-platinum complexes and their use as antitumor agents in humans and animals.
It is known that Cisplatin, cis-[Pt(NH.sub.3).sub.2 Cl.sub.2 ] is effective against several types of animal tumors and has been used successfully in treating certain types of malignancies in humans. A number of other platinum complexes have been tested for antitumor activity, e.g., increased life span for mice having implanted tumors such as L-1210 lymphoid leukemia.
An oligomeric platinum complex is disclosed in U.S. Pat. No. 4,128,342 to Yolles. These complexes contain bridging halogen ligands as well as a number of platinum ions in both therapeutic and non-therapeutic forms in the complex.
Three bis-platinum complexes were reported by Rochon et al., J. Clin. Hematology & Oncology, 12, 39-43 (May, 1982). Two of those showed no activity against L-b 1210 lymphoid leukemia, while a third showed a low level of activity but also showed significant toxicity.
U.S. Pat. Nos. 4,115,418; 4,137,248; 4,169,846, 4,200,583; 4,256,652; and 4,322,362 disclose monomeric complexes of [1,2-diaminocyclohexane]Pt (II). Other patents disclosing organoplatinum compounds, mostly as having antitumor activity include U.S. Pat. Nos. 4,225,529; 4,230,631; 4,250,189; 4,255,347; 4,271,085; 4,283,342; 4,359,425; and 4,410,544. The disclosure of the foregoing patents relating to their use in antitumor therapy are incorporated herein by reference.
A need continues to exist for platinum complexes having appreciable water solubility to facilitate intravenous injection, along with significant antitumor activity and low toxicity.